Over the course of the six years or so the developmental portion of the WWE has gotten face lift and at this point may mean more then some main roster brands. However, even in all the good that Triple H has done since taking over the developmental territory their still has been a good amount of bad wrapped up in all that good. The first mistake that was made which comes to mind is Adam Rose. For those who don't know Adam was a veteran of the WWE developmental region having spent time in another territory during his time with WWE before NXT. Many thought that Adam wouldn't make up to the main roster as some didn't feel he had the complete package so they change his gimmick.
From the time he arrived with the WWE the man named Leppan would be called Leo Kruger; which was chosen as tribute to South African President Paul Kruger. It wasn't long after his name change to Kruger that he would begin to build momentum to becoming a top star in FCW. While a member of FCW, Kruger would win the World Title on two separate occasion the second coming not long before the re-branding of FCW to NXT. Once the territory made the change Leo kept his name and gimmick the same and would remain a top star in NXT.
It was in August of 2014, when everything changed because Leo was removed from Television and started working house shows under a new gimmick and new name. The new name was Adam Rose. Adam's gimmick was that of a "Party Animal" and vastly different from the gimmick he had as Leo Kruger. But with the gimmick change he was soon promoted to the main roster and given a few month unbeaten streak. However, within a year of his promotion to the main roster Rose would be fired from the company.
Though in the end Rose was to blame for his release in the long run I do believe that they would have gotten more longevity out of Adam had they not switched his gimmick and just kept him as Leo Kruger. In hindsight it's pretty someone in the WWE "Was a lemon and not a Rosebud!"